Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying. -- Arthur C. Clarke
In the next part of our story we expand our perspective to include the whole galaxy. By the late Federated Era, humanity is spread through much of the solar system. Major centers of civilization have established their own local blockchains and higher-order, longer-timescale blockchains such as Solcoin are an interplanetary market. Is this series of developments unique to humankind? If there are other technological civilizations in our galaxy, will they also develop an equivalent of bitcoin, Solcoin, &c?
Any speculation for extraterrestrial life and civilizations is biased by our own understanding of ourselves. NASA's maxim for finding life in our solar system -- Follow the water -- assumes life elsewhere requires liquid water because we do. SETI's electromagnetic vigil assumes civilizations elsewhere use narrow-band radio signals because we do. Searching for life in the first place assumes it exists because we do. Listening assumes life elsewhere wants to be heard because we do.We cannot escape our biases but we can temper them with the knowledge that extraterrestrials, should they exist or arise, must operate by the same rules of this universe as we do. To avoid anthropomorphism (or "terramorphism"), we must therefore attempt to identify universals -- properties which must characterize life and civilization anywhere they occur. Asking if other civilizations will develop blockchains is a way of asking whether we believe blockchains to be universal across technological species.Unfortunately, given our samples size of one biosphere and one (young?) civilization, it is extremely difficult to agree upon proposed universal properties of life. For example, even though all life on Earth universally requires liquid water and relies upon the same biochemistry, we have no idea whether life elsewhere must be similar. Given the scale of the (potentially infinite) universe it's possible there are no universal properties of life. We may be completely alone in the universe, a temporary statistical fluke in entropy production needing neither explaining nor purpose. Or perhaps abiogenesis is as unpredictable as the decay of a quantum state, as fecund as white noise, and the universe is full of life that is incomprehensible to our physics & biology; beings we cannot grasp experiencing realities we cannot conceive.Given our current lack of observational data, whether you believe there are no universals or many, your belief perhaps says more about you than it does about the universe.
Astrobiologists are scientists who study the possibility of and actively search for extraterrestrial life. They often express their beliefs about universal properties for life and civilizations using the Drake equation:[caption id="attachment_1017" align="aligncenter" width="300"]
The Drake equation was created by Frank Drake to spur speculation among scientists about how to detect alien signals.[/caption]The Drake equation is a particular way to encode your beliefs about astronomical, biological, social, and technological universals into a prediction of the number of detectable extraterrestrial civilizations we should currently expect to observe in our galaxy. The first parameter, for example, R*, is the rate of formation of new stars. The presence of this number implies accepting the universal that life forms around stars. The second parameter, fp, is the fraction of stars which have planets. This implies accepting the universal that life forms on planets. Two parameters in and the Drake equation has already excluded the possibility of plasma whales evolving in the hot clouds of black hole accretion disks.Astrobiologists find this to be a reasonable trade-off. Yes, the universe may contain strange and wonderful life unlike us that doesn't evolve on planets orbiting stars. But constraining our attention to the subset of planets, lifeforms, and societies like our own, allows us to be more quantitative.Astronomers believe there are millions, potentially billions, of habitable planets just like Earth in our galaxy alone. And life got started almost immediately on our planet, indicating that it was either already around or that it is easy for life to get started if the conditions are right. Life may even have gotten started on other planets or moons in our own solar system -- it may be living there now. Life is probably extremely common.
Simple life could be present everywhere in our galaxy and we would reasonably not have detected it yet -- our telescopes are only now on the cusp of being able to resolve the signatures of a planetary biosphere from light years away. But technologically advanced life is active on the galactic scene. A long-lived civilization capable of slow (~1% the speed of light) interstellar travel would have had plenty of time to explore and colonize the entire galaxy by now. We should see evidence of their activities everywhere. In particular, they should certainly have already explored our own solar system. Enrico Fermi's famous lunchtime quip -- if interstellar civilizations are common then "Where is everybody?" -- is nowThe last few parameters in the Drake equation, fi, fc, and L, describe our beliefs about how universal the evolution of intelligent, technological civilizations is and how long these civilizations last. We don't have precise ways of estimating these parameters but we suspect their product is relatively small compared to that of the prior parameters in the equation. This is for two reasons.The first is that the existence of our own technological civilization seems more conditional and less inevitable than that of simple life. Once it evolved, simple unicellular life dominated the Earth for billions of years, a significant fraction of the age of the universe. Animals and plants only evolved comparatively recently. Animals are still, today, a smaller fraction of Earth's biomass than even single-celled protists, humans smaller still. Humanoids evolved for millions of years before they discovered fire, language, & technology and were almost wiped out several times. And there is still a chance that we may destroy ourselves. Our own history as a species suggest that technological civilizations may not be common and may not be long-lived. We may live in a galaxy of algae.The second reason is much more interesting. In the absence of direct experimental data about these parameters scientists use a form of indirect reasoning to try and put upper bounds on their values. This reasoning was first formalized by Michael Hart and runs, briefly, as follows:
A similar argument can be made for interstellar communication instead of travel. Two differences are we already know that interstellar communication is possible and the analogue to "Fact A" ("There is no evidence of alien life communicating with Earth") is less well-supported. Some scientists still reach similar conclusions: b) no civilization chooses to communicate with others c) we are the only intelligent, technological civilization in our galaxy at the present time.This kind of reasoning is the heart of the Fermi Paradox: if civilizations are common in the galaxy, then "where is everybody?" What is fascinating about this form of reasoning is how much it depends on assumptions about the behavior of other civilizations. We cannot scientifically answer this question, only speculate based on our understanding of our own civilization. In this way speculating about extraterrestrial civilizations is like holding up a mirror to our own. To quantify the probability of life we needed to identify the aspects of life we believe to be universal. Similarly, to engage in the kind of reasoning above we need to identify what aspects of civilization are universal.SPOILER ALERT: The following contains some details of the plot of Cixin Liu's thought-provoking novel The Dark Forest, sequel to the The Three Body Problem.The author Cixin Liu gives a wonderful name to this mode of reasoning in his novel The Dark Forest: Cosmic Sociology (no doubt a department in the same building as Bitcoin Astronomy). As one character explains, when there is "nothing concrete to study" and "surveys and experiments aren't possible," then the "ultimate result will be purely theoretical." She goes on to describe her "axioms" for and deductions in cosmic sociology:
This is Cixin Liu's terrifying resolution of the Fermi Paradox. It's not science but it is compelling science fiction because Liu's choice of universals creates a reflection of our own civilization, recognizable yet dark. Perhaps the deductions above say more about Cixin Liu the author or US-China politics than they do aliens.
The last few parameters in the Drake equation are under-constrained. We cannot measure them directly and cosmic sociology approaches will always retain some measure of subjectivism, preventing us from using Hart's "Fact A" above to conclude we are alone: absence of evidence is not evidence of absence. A recent paper by Carroll-Nellenback, et. al (2020) is one of the most thorough analytical treatments and numerical simulations of a technological civilization expanding through the galaxy to date. It concludes that there are "areas of parameter space" -- choices of universals -- that lead to us being alone in the galaxy OR the galaxy being full of life and us not having noticed it. We simply can't tell yet.[caption id="attachment_1018" align="aligncenter" width="1006"]
A plot simulating civilizations spreading through the galaxy. The red area represents choices of parameters where we are alone in the galaxy while the blue area represents choices where the galaxy is completely saturated with life. Boundary areas exist representing choices where the universe is full of life but also sparse. The point is that we are free to speculate since many different possibilities are still realistic given the current body of observational data.[/caption]The happy result is that we are free to speculate, to engage in cosmic sociology by choosing universals which reveal our own biases. Since our goal is to return to the story of hyperbitcoinized humanity and their spread through the solar system, we should choose to explore universals which lead to the best speculations. Let us say:
It is fair to object that our choice of universals is clearly biased to support economic speculations about how other civilizations will manage their money. Yes, this is true, but just as xenobiologists choose to study life on planets around stars because it's the life they can understand, we choose to speculate on civilizations that use money because we have a better chance at understanding them. This series is called "Bitcoin Astronomy," after all.This choice may not be as narrowing as one fears -- Nick Szabo writes in "Shelling Out" that a social species' fitness is increased by the advent of early monies as a way of engendering reciprocal altruism. Perhaps any civilization social enough to communicate over interstellar distances has evolved money. But what would it look like?
Would alien civilizations invent bitcoin?In evolutionary biology, a question about why or how some adaptation developed can be plausibly explained in many ways. Sometimes we can lend support to these stories through the fossil record. If the same adaptation appears in several different species at several different times due to similar environmental pressures it is easier to conclude that the environmental pressure caused the adaptation. This is not always possible.Why did the giraffe's neck grow so long? Because giraffes with longer necks could reach more leaves making them more fit and causing their genes to replicate. It's difficult to know whether a particular "just so" story is really correct.When speculating about the evolution of technology in alien species we are in a similar situation, being able to tell plausible stories but not having a "technology fossil record" to support our conclusions.As an illustration, we might ask would another technological civilization develop nuclear fusion? By construction, we are considering civilizations who can send and receive signals through space. Such a civilization would know about stars and would eventually realize why they shine. Like us, they would recognize what a valuable source of energy fusion is and try to develop it themselves. So we can tell a "just so" story about nuclear fusion to convince ourselves that it is a universal that all technological civilizations will eventually discover.Can we tell a similar story about bitcoin?
NOTES:https://www.technologyreview.com/s/614259/an-important-quantum-algorithm-may-actually-be-a-property-of-nature/?utm_term=Autofeed&utm_campaign=site_visitor.unpaid.engagement&utm_medium=tr_social&utm_source=Twitter#Echobox=1569211518
